X-ray radiation sources are well known and employed in numerous applications ranging from medical imaging and diagnostic to industrial radiography and material analysis among others. Examples of such X-ray radiation sources are X-ray tubes which are the most commonly used X-ray radiation sources in medical facilities.
However, many sources, including X-ray tubes, have inherent limitations coming from their use of the Bremsstrahlung effect to generate X-rays. These sources can only generate broad band energy spectra, have a large source size which limits the maximum resolution and a low brightness, to name only a few.
Other sources have been developed including radioactive sources, synchrotron facilities and particle accelerator Compton sources. However, all these alternatives have strong drawbacks which limit their widespread use. For instance, radioactive sources contain potentially hazardous materials whose storage and use involve strict regulations. Synchrotron facilities and Compton sources are usually large facilities which can not foe easily used in industrial and medical environments.
Knowing these limitations, several attempts have been made over the years to develop table top sources that would show better characteristics.
Radiation sources based on laser driven plasma accelerators are promising candidates, given the compactness and low cost of these systems, and several attempts to design such sources have been reported.
In particular, Compton scattering (also called Thomson scattering) a photon beam off a relativistic electron bunch produced by a laser driven plasma accelerator has been proposed as a source of high-energy and high-brightness photons, using the modest electron energies obtained with existing laser systems.
“Thomson-backscattered x-rays from laser-accelerated electrons” to H. Schwoerer, B. Liesfeld, H-P. Schlenvoigt, K-U. Amthor & R. Sauerbrey (Phys. Rev. Lett. 96, 014802 (2006)) discloses such a Compton scattering scheme using two lasers pulses, the first laser pulse driving the plasma accelerator the second laser pulse achieving Compton scattering of the accelerated electron beam.
However, such laser-plasma based approaches to Compton scattering have not, to-date, produced x-rays above a kilo-electron-volt and their specifications, in terms of reliability, brightness, tunability, spectrum or repetition rates, have currently prevented them from achieving commercial success.
The present invention aims at improving this situation by providing a novel method for producing electromagnetic radiation as well as a novel electromagnetic radiation source.